Yawning is like a social signal. When you see someone yawn, your brain thinks it's time to yawn too, just like when you laugh with friends or cry together. It's almost like your brain is saying, 'I'm feelingtired too!'Sometimes this happens even if you're not sleepy at all.
How It Works
Your brain has special cells called mirror neurons that help you copy other people’s actions. When someone yawns in front of you, these mirror neurons kick into action and make your body follow suit, poof, you start yawning too!